docs: async def read_tree_updating_working_copy(self, tree, force):
          '''This method relies on the current working copy being clean with
          respect to the current index. The benefit of this over
          checkout_missing_files_from_index(), is that is clean up files that get
          deleted between the current tree and the new one. Without force, this
          raises an error rather than overwriting modified files.'''
          if force:
              await self.git('read-tree', '--reset', '-u', tree)
          else:
              await self.git('read-tree', '-m', '-u', tree)